Formation sampler and valve system



May 31, 1966 cs. E. BRIGGS, JR, ETAL 3,253,654

FORMATION SAMPLER AND VALVE SYSTEM Filed Sept. 15, 1962 FIG. 2

GEORGE E. BRIGGS JR.,

MAURICE L. FORD, &

DAVID R. WARREN.

INVENTORS,

BY a g FIG. I ATTORNEY.

United States Patent 0 FGRMATION SAMPLER AND VALVE SYSTEM Qeorge E. Briggs, 3L, West University Place, and Maurice L. Ford and David R. Warren, Houston, Tex., assignors to Hailiburton Company, Duncan, Okla, a corporation of Delaware Filed Sept. 13, 1962, Ser. No. 223,497 16 Claims. (Cl. 166-100) The present invention relates to sampling of the fluid content of earth formations and, more particularly, to wireline apparatus for taking fluid samples laterally of a borehole piercing the earths formation of interest.

Such a device and system is useful in that formations about a borehole at various depth zones may be selectively sampled to determine fluid content. Information derived from such samples is useful in evaluating the probable fluid productivity of such zones and, hence, is a valuable aid in selecting, from such zones, those having the best production potential for final completion.

Apparatus of this general type adapted for lowering in a borehole by means of a wireline and having provision for utilizing the hydrostatic pressure energy of its sampling environment for actuating power is well known and has long been recognized as potentially providing a more facile, eflicient and economical means of formation sampling than similar apparatus lowered by means of a tubing string. The prior art, however, has not enabled the attainment of a sampling success efficiency in practice which is commensurate with this long-recognized potential.

Among the numerous causes of failure experienced with prior art devices of this general type, the most serious failure has been found to be loss of surface control over the operation of the device due to electrical grounding of control signals and/or failure of an electro-mechanical component upon which such signals directly operate. A failure of this type in the latter stages of a sampling sequence, when the device is still in anchored sealed engagement with the borehole wall, may be disable effective control to the extent that the device may not be removed from the borehole without an expensive fishing operation. It will be appreciated that fishing operations are not sure of success and that failure of effective surface control may result not only in the abortion of the sampling operation and the loss of the sampling device, but possibly in the effective loss of the entire well.

Accordingly, it is a principal object of this invention to provide a new wireline formation fluid sampler device of improved general effectiveness, efliciency and reliability and having a new construction and mode of operation not provided in prior art devices.

Another object of the invention is the provision of a new and improved sampler device initially controllable from the earths surface in its sample taking sequence by a first telecontrol link and ultimately controllable in the latter portion of its sample taking sequence by a second telecontrol link, different in kind from said first link, whereby said latter portion of said sequence may be successfully carried out without regard for failure of said first link.

Still another object of the invention is the provision of a new and improved wireline sidewall sampler device embodying a secondary control system for controlling the sequence of functions necessary or desirable for the successful completion of a wireline sampling operation, subsequent to the filling of the sample chamber of the device, responsive to wireline tension for initiation, but independent of wireline tension insofar as actuating power is concerned.

A further object of the invention is the provision of a new and improved wireline sidewall sampler device em- 3,253,654 Patented May 31, 1965 'ice bodying a secondary control system for performing a sequence of hydraulic control steps including the hydraulic shocking of the device in order to faciiltate retraction of bore sidewall engaging members thereof prior to withdrawal of the device from the borehole.

A still further object of the invention is the provision of a new and improved sidewall sampler device providing sequence valve means and shocking means adapted for hydraulic actuation responsive to a wireline signal, with the further provision of means to lock said valve means in its actuated condition to thereby prevent the inadvertent return of said valve means toward its previous unactuated disposition.

Still another object of the invention is the provision of a new and improved sidewall sampler device adapted for hydraulic actuation responsive to initiation by a wireline movement signal, with the further provision of means for indicating the magnitudes of any said movement signal.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodimen about to be described, or will be indicated in the appended claims and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

A preferred embodiment of the invention has been chosen for purposes of illustration and description. The preferred embodiment is not intended to be exhaustive nor to limit the invention to the precise form disclosed. It is chosen and described in order to best explain the principles of the invention and their application in practical use to thereby enable others skilled in the art to best utilize the invention in various embodiments and modifications as may be best adapted to the particular uses contemplated.

In the accompanying drawings:

FIGURE 1 is a schematic illustration of a wireline formation fluid sampling device embodying features of the present invention and showing the device in an actuated disposition with respect to the walls of a borehole preparatory to obtaining a formation fluid sample; and

FIGURE 2 is a schematic illustration of a part of the device illustrated in FIG. 1 in its operated position.

Described generally, the formation fluid sampler device embodying the present invention, as shown in FIG. 1, comprises a downhole sampling device generally indicated as 19 (and including a lower body 11 and an upper body 11') shown suspended from the earths surface within a borehole by means of a wireline 14 from sheave 17 and Winch 18. As is conventional and, therefore, not shown, the device 10 is controllable by means of electrical signals originating in surface electronic equipment and communicated by means of a central conductor of wireline 14 to suitable downhole electronic equipment housed in the device 10.

It is to be understood that the showing of borehole 12 is an open hole is merely for the purpose of illustration and that the device 10 is useful in either open holes or cased holes penetrating the earths surface so long as such boreholes contain fluid (either liquid or gas) under sufficient pressure for proper operation of the device, which, in the main derives its operating power from pressure energy of a fluid environment but which is corn 7 trolled from the earths surface.

The formation fluid sampler device 10, at its lower end, is comprised of a fluid pressure source section 26 which is adapted to supply an incompressible actuation pressure fluid by means of a dilferential area intensifier incorporated therein.

A sampling section 28, located immediately above the source section 26, schematically represents a well known design fully described in Patent No. 2,674,313 to Chambers. The sampling section provides a resilient forma- 3 tion isolation pad 30 and a wall engaging plate member 32 which are mounted on the device by means of reciprocally movable plunger or actuator rods 33 which extend from within actuator fluid chambers 34. The actuator fluid chambers 34 are communicated with each other and with the source section 26 by means of a flow path 27 which is closed by an actuation valve 36 prior to the time that actuation of the sampling section 28 is desired. At this time, the valve 36 is opened and fluid pressure from the source section 26 extends the rods upon which are mounted pad 30 and plate 32. Prior to actuation, the rods 33 are normally maintained retracted 'within the actuator fluid chambers 34 by the force of retraction springs 38 exerted to maintain the members 30 and 32 retracted against the body of the sampler device. When fluid pressure from source 26 is applied to the rods 33, the members 30 and 32 are forced into anchored engagement with the walls of the borehole 12.

The formation isolation pad 30 is adapted to seal off an area of the borehole wall when forced thereagainst.

An opening 40 is provided centrally of the face of the pad 30 and comprises a portion of a formation sample flow channel 42 which extends from the face of the formation isolation pad 30 upwardly within the body of the formation sampling device through a control section 43 into a chamber 44 in sample chamber section 45. The chamber 44 is provided for receiving the desired sample of formation fluid. Flow channel 42, in communicating from the opening 40 to the sample chamber 44, successively communicates through a flexible section adapted to accommodate relative movement between pad 30 and lower body 11 (such a section is well known in the art as exemplified by the patent to McMahan, cited infra), an equalization valve 46, a normally closed sample flow valve 48 and a normally open fluid sample shut-in valve 50.

These valves are conventional in fluid sampling devices' and have the following well known functions. The equalizer valve 46 serves to normally maintain fluid flow integrity of the channel 42, but, when actuated, serves to open the channel 42 to a channel 47 which communicates to ambient fluid pressure externally of the fluid sampling device to therethrough equalize fluid pressures across the face of the pad member 30 and facilitate retraction thereof. The normally closed sample flow valve 48 serves to normally block fluid flow in the channel 42 from the formation under test to the sample chamber 44, but, when actuated, permits fluid flow thereto'. The normally open fluid sample shut-in valve 50 serves to normally permit flow in the channel 42, but, when actuated, serves to block the flow of fluid therein to thereby shut in or capture any fluid sample present within the chamber 44.

A chamber containing a compressible fluid at a low pressure, which is substantially less than the pressure supplied from the pressure source section 26, may be provided within the control section 43. A fluid channel 54 provides a communication path connecting the fluid within the chambers 34, by way of a branch passageway 54A to the chamber 52. This communication path to the chamber 52 is normally blocked by a valve 57, but, when the valve is actuated, the fluidwithin the chamber 52 is communicated with the fluid of the chambers 34 and equalization of pressures within the chambers 34 and 52 is obtained. When the valve 57 is actuated and the chambers 52 and 34 are equalized, the pressure in the chambers 34 is lowered considerably below the hydrostatic pressure of the borehole and the differential pressure between hydrostatic and the lowered pressure within the chambers 34 operates to force the plungers or rods 33 back into their respective chambers and retraction of the wall engaging members 30 and 32 ensues.

Although the various valves 36, 46, 48, 50, and 57, indicated schematically in the drawings, may be of any suitable remotely controllable type, valves which are initiated by means of an electrical signal and which actuate responsive to fluid pressure energy of the borehole fluid environment are to be preferred in that they obviate the need for transmitting large amounts of power by means of the electrical conductor of wireline 14 from the earths surface. Valves of this type are well known in the art, having been disclosed in commonly assigned Patent No. 2,982,130 to McMahan which discloses valves suitable to each of the foregoing functions.-

As has been indicated, the device 10 includes a lower body 11 and an upper body 11. The body 11 is provided with a complex longitudinal bore which extends downwardly therein from the upper end thereof. This bore, beginning at its upper end, is successively comprised of an upper seal bore portion 60, a spring cavity counter bore portion 61, a lower seal bore portion 62 and valve bore portion 63. The longitudinal extents of these various bores are defined by shoulders therebetween. upper seal bore portion 60 extends from the upper surface of the body 11 to a shoulder 65 at which the spring cavity counter bore portion 61 commences. The spring cavity counter bore portion 61 extends from the shoulder 65 to a shoulder 66 which defines the commencement of a lower seal bore portion 62. The lower seal bore portion 62 extends from the shoulder 66 to ashoulder 67. A valve bore portion 63 extends from the shoulder 67 to a blind end which terminates the complex bore.

The upper body 11 is provided with depending extension which telescopically engages within the' just described somewhat complex bore of body 11. This engagement, as will be seen, provides a point which permits a limited amount of relative movement to take place between the lower body 11 and the upper body 11. The

I extension is successively comprised of a tension rod portion 70, sized for sealing slidable engagement within upper seal bore portion 60; a balance piston 71 (located at the lower extremity of the tension rod portion 70) which sealingly and slidably engages within the spring cavity counter bore portion 61; an unbalance piston 72 contiguous to the lower surface of the balance piston 71 and in sealing slidable engagement within the lower seal bore portion 62; and a valve extension 73 depending from lower surface of the piston 72 and in sealing slidable engagement within the valve bore portion 63. The bore 60 is provided with an O-ring seal 60 for sealing the tension rod 70 in its movements therethrough. The balance piston 71 is provided with an O-ring 71' for sealing the same with respect to the spring cavity counter bore portion 61. The unbalance piston 72 is provided with an O-ring seal 72' for sealing the same with respect to lower seal bore portion 62.

The upper body 11' and the lower body 11 are maintained in normal relative positions by a coiled spring 76 interposed in biased relation between the shoulder 65 and the upper surface of balance piston 71 within the spring cavity bore portion 61. The spring 76 normally maintains the'lower surface 80' of piston 72 in abutting contact with the shoulder 67 to define the aforementioned normal relative positions. As shown, the spring 76 is coaxially disposed within annular cavity 76' whose outer walls are those of spring cavity counter bore portion 61, whose inner walls are the exterior of the tension rod 70, whose upper extremity is the shoulder 65 and whose lower extremity is the upper surface of the balance piston 71. Within the space unoccupied by the coiled spring 76, the annular spring cavity is filled with a compressible fluid of negligible pressure. As relative movement takes place between the upper body 11 and the lower body 11, the volume of the spring cavity 76 diminishes in size and compresses the spring 76 as well as the low pressure compressible fluid therewithin. However, because the pressure of the compressible fluid in its compressed condition is still at a negligible pressure, the force resisting the relative movement is provided by the spring 76, to the O substantial exclusion of any force due to the compressible fluid.

The upper body 11 and the lower body 11 are maintained in the aforesaid normal relative positions by the spring 76 which exerts a preload force of about 2,500 pounds. This force has been found to be satisfactory in that in addition to supporting the weight of the body 11, it provides an excess to resist other forces, which may be inadvertently applied while lowering the device into the borehole, tending to disturb said normal relative positions.

A port 78 in the side of the lower body 11 communicates borehole fluids to an annular balance chamber 79 defined by the outer walls of the spring cavity counter bore portion 61, the outside diameter of the unbalance piston 72, the shoulder 66 and the annular surface 80 defined between the diameters of the piston 71 and piston 72. The diameters of the piston 71 and the piston 72 are sized such that their difference, the annular area 89, is equal to the area of the tension rod 70. With this relationship, when the device 10 is submerged in borehole fluid, the force of borehole fluid pressure urging the tension rod 70 downwardly within the bore of lower body 11 is balanced out by the force of borehole fluid pressure operating on or wetting the annular area 80. This latter force, of course, is directed upwardly on the extension of the upper body 11' to thus cancel any borehole fluid force effects which may tend to alter the operation of the device 10 insofar as the relative positions of the bodies 11 and 11' or the force required to secure relative movements thereof.

Thus, it is seen that the compressible fluid within the spring cavity 76' is of negligible effect in restraining the relative movements of the body members 11' and 11 and that the force eifects of borehole fluids, as they might effect the relative movements of the bodies 11' and 11 in their normal relative position is balanced out by the relationship of the area of rod 70 and the annual area 80. Thus, the only force acting on the two bodies 11' and 11, insofar as their relative movement is concerned, is the force of spring 76 urging these bodies toward their normal relative positions as has been described.

With the bodies 11' and 11 in their normal relative positions, as just described, the valve extension '73 is maintained with respect to the valve bore portion 63 in a corresponding normal position. In this corresponding relative position, flow channel 42, in communicating from the pad member 30 to the sample chamber 44, communicates from lower body 11 to upper body 11 by means of a first lateral extending portion 42' of flow channel 42 located within lower body 11 and a second lateral flow channel portion 42" which fluidly communicates when the valve extension 73 is in the said corresponding rel ative position with respect to the valve bore portion 63. However, upon the occurrence of relative movement between the body 11 and 11, the lateral flow channel 42" moves upwardly with respect to the lateral flow channel 42' and fluid communication is cut off through the flow channel 42 to accomplish a shutting in of any fluid samples which may be present in the sample chamber 44.

Valve extension 73, for purposes of clarity and simplicity of illustration and description, is shown provided with transverse flow passageways for interconnecting the various fluid channels of the sampler device. It will be appreciated, by those of ordinary skill in the art, that the valve extension desirably would take the Well known practical form of a conventional spool valve member having annular groove type flow control passageways separated by lands provided with O-ring grooves and seals for fluidly isolating the various control passageways of the fluid system. Such conventional spool valve construction is well known in the art as exemplified by Patent No. 2,640,542 to Brown et al., therefore to show such well known detail would merely complicate the illustration and description.

An equalization passageway 82 is provided which communicates from the exterior of the lower body 11 to the valve bore portion 63, at a level generally opposite the flow Channel portion 42, but is normally blocked by the surface of the valve extension 73. The valve extension 73 is provided with a transverse flow channel 82 which, although normally disposed below the level of equalization passageway 82 and flow channel portion 42, establishes fluid communication between equalization passageway 82 and the lateral portion 42 of flow channel 42 upon the occurrence of a predetermined amount of relative movement to thereby establish fluid communication from opening 40 to the fluids of the borehole exterior to the body 11. When this lateral communication is established, the fluid pressure across the face of the sealing pad member 30 is equalized with respect to the pressure of borehole fluids.

As has been brought out, fluid channel 54 is comprised of a first branch 54A which communicates with the low pressure chamber 52. Fluid channel 54, in addition, has a second branch passageway 54B. Branch fluid channel 543 has a laterally extending portion which communicates with the valve bore portion 63 and, thence, to the chamber 52. However, this lateral extension of the branch channel 54B is normally blocked by the valve extension 73. Valve extension 73 is provided with a passageway 5413' which, when the valve extension is displaced with respect to the valve bore portion 63, permits fluid communication in the branch channel 548 to accomplish pressure equalization between the chamber 52 and the chambers 34.

It is to be noted that, during the relative movement of upper body 11' and lower. body 11 and by virtue of the different effective widths of the lateral flow channel 42", the passageway 82' and passageway 54B, the various valving operations, i.e., the blocking of communications through the channel 42, the establishment of communication between passageway 82 and the channel 42 and the establishment of fluid flow in the branch channel 543 take place in sequenced relation to one another. The preferred sequence is such that the sample in chamber 44 will be shut-in first, the equalization of pressure across the face of the sealing pad 30 will occur next, and the fluid communication between the chambers 34 and the chamber 52 will occur last. This sequencing is desirable for most effective operation in extricating the device 19 from the walls of the borehole with a captured sample.

The aforementioned valving functions of the valve extension 73 are illustrated in FIG. 2, wherein the valve extension 73 is shown in its second or operated disposition with respect to the valve bore portion 63, the body 11' having been moved with respect to the body 11 the aforementioned limited amount.

Assuming that the device 10 has been lowered to a desired point within the borehole from which a fluid sample is desired, the actuation valve 36 is operated responsive to an electric signal communicated thereto from the earths surface. This permits high pressure fluid within the pressure source section 26 to communicate to the chambers 34 and operates to extend the rods 33 therefrom. The force exerted on the rods 33 is sufficient to set the pad member 3t) and the plate member 32; against the walls of the borehole, to anchor the device 10 therein and to seal off an area of borehole wall with respect to borehole fluids within the limits of the sealing pad 30. When the device has thus been anchored and sealed with respect to borehole walls, the sample flow valve 38 is actuated pursuant to a signal from the earths surface in a manner similar to the actuation of valve 36. This permits fluid samples to flow from within the formation sealed off within the isolated area through the sample flow channel 42 into the chamber 44. When the chamber 44 has been filled, the operator at the earths surface may complete the operating sequence of the device 10 by means of either electrical or wireline signals. If the former control is elected, an electrical signal would then be sent to close the normally open valve 50 to capture any sample fluid in the chamber 44, a second signal would be transmitted to actuate the equalization valve 46 so that borehole fluids would be communicated to the sample line 42 and a third signal would be sent from the earths surface to actuate the valve 57 to accomplish equalization between the chamber 52 and 34, in that order. This last mentioned electrically controlled sequence is well known in the wireline formation sampler art as one means of preparing a sampler for removal from the borehole.

As his other option, the operator may elect to prepare toward normal relative positions, a lock-out means is provided to lock these bodies in their actuated relative posithe device 10 for the retrieval from the borehole by means of a wireline tension signal to initiate the actuation of the control section 43. One reason for exercising this latter choice might be the inoperability of the electrical control system provided for operation of the conventional control. To implement this election, a force must be exerted on the wireline M somewhat in excess of the preload force on spring 76. When sufficient force is exerted, the body 11 moves with respect to the lower body 11 and compresses the spring '76. During the first portion of the relative movement, the movement is entirely responsive to the tension in the wireline in excess of the force of spring 76. As the movement continues, the O- piston 72, in addition to being exerted on the annular area it the normal balance of the force system is dis-. 'turbed and the upper body 11 is moved upwardly with respect to the lower body 11 in response to an unbalance force equal to the intensity of hydrostatic borehole fluid pressure times the effective area of the unbalance piston 72, specifically the area 80 thereof. This unbalance force is of great magnitude (of the order of 6-10 times the weight of the device 10) because of the intense pressure of borehole fluids at the depths at which fluid samples are normally desired. The result of this high magnitude force is to impart high acceleration to the relative movement of the two body portions of the device 10. Upon the stacking of the spring, the relative movement is abruptly brought to a stop and a high upwardly directed shock force is imparted to the body 11 by the abruptly stopped body 11. This high shock force is transmitted through the body 11 to the wall engaging members of the device and is highly effective in jarring the wall engaging members and 32 from engagement with the borehole wall. This jarring effect greatly facilitates the retrieval of the sampler device 10 from the borehole.

Of course, the aforementioned valving functions are also performed in the aforementioned sequence prior to the shock force being imparted to the body 10. Thus, the control section 43, in addition to performing the desired sequence of shut-in, pad equalization and retraction, lastly performs a jarring operation as a concluding function within its sequence. This jarring effect is, of course, not obtainable with the conventional sequence of operation.

As the device 10 is withdrawn from the borehole, the hydrostatic pressure of the borehole fluid environment becomes less and less as the surface is approached. When this pressure is sufliic ently reduced in value, the energy stored in the stacked spring 76 tends to overcome the force of fluid pressure maintaining the bodies 11' and 11 in their respective actuated relative positions and to return the bodies to their respective normal relative positions. This tendency to return to normal relative positions is undesirable in that an operator might be misled by appearances and fail to redress the control section after it is operated. To obviate the chance of return tions. A convenient device for accomplishing the lockout at the end of the actuation stroke is shown in FIG. 1 to be comprised of a spring type locking ring 84 which is normally maintained in a compressed configuration within a groove 85 in the tension rod 70. The groove is located such that when the body 11' is in its normal relative position with respect to the lower body 11, it is within the upper seal bore 60 and the locking ring 84 is maintained in compressed condition therewithin, much like a piston ring on a piston, such that the tension rod 70 is readily slidable therein. However, when the member 11 undergoes the aforesaid limited amount of relative movement, the groove 85 projects beyond the upper surface of the lower body 11 and thelocking ring 84 is permitted to readily expand. When this expansion occurs, the body 11' is prevented from returning to its normal relative position with respect to the body 11 by the resulting pro-- iection.

A relative movement indicator 87 interconnects upper body 11' with lower body 11. Its purpose is to indicate whatever degree of relative movement between the two bodies that may transpire while the device 10 is within the borehole. The indicator will indicate the maximum amount of relative movement that may take place. Indicator 87 isshown to be in the form of a coiled member of ductile material which permanently deforms substantially in proportion to the relative movement of the bodies 11 and 11'. Copper has been found to be a suitable material for making a satisfactory indicator of the coiled configuration as shown.

The sampler device 10 may be satisfactorily operated with the lock-out ring 84 (without the indicator 87) to positively prevent the relatively movable bodies 11' and 11 from completing a misleading excursion of relative movement and, thus, positively indicate that the control section 43 has been operated by means of the change in spacing of the bodies 11' and 11. This puts an operator on notice that the various seal elements of the control section 43 may need redressing prior to another sampling operation. I

Likewise, the device 10 may be satisfactorily operated with only the indicator 87 (Without use of lock-out ring 84) to indicate any maximum degree of relative movement between the body members 11 and 11', even though this maximum may fall short of the relative movement required to set the locking ring as described in the previous paragraph.

Desirably, the device 10 would employ both the lockout 84 and the indicator 87 to accomplish a lock-out when the members 11 and 11 make the complete limited amount of relative movement and to indicate the maximum extent of any movement even though it may fall short of this limited amount.

Thus, it has been seen that the invention provides a new and improved formation fluid sampler device of improved general effectiveness, efliciency, and reliability, and having a new and unique construction and mode of operation; that these improvements stem from a telecontrol system which is effective to control the later portion of sampling operation sequence and to exert this control in a highly effective manner such that this portion of the sampling sequence may be carried out with improved reliability; that this new telecontrol link includes a sequence valve means which is initiated responsive to wire- -line tension, but which actu-ates responsive to the presin wireline sampler devices or it may be used as a primary means of controlling the entiresampler device in the later, but most important, stages of a sample taking sequence.

As various changes may be made in the form and construction herein described without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in any limiting sense.

What is claimed is:

l. A device for obtaining samples of the fluid content of formation traversed by a borehole containing a fluid comprising: a support adapted to be suspended in a borehole by means of a wireline from the earths surface; a chamber in said support for retaining a fluid sample; means on said support responsive to fluid pressure for anchoring said support with respect to the borehole wall and for isolating a portion of the borehole wall with respect to borehole fluids; a first fluid channel for conducting a formation fluid sample from within said isolated portion of borehole wall to said chamber; a second chamher in said support containing a fluid under hi h pressure for pressurizing said means; a second fluid channel in communication with said second chamber for communicating pressurized fluid thereto; a third chamber in said support containing a compressible fluid at a pressure substantially less than that of the hi h pressure fluid; a third fluid channel for connecting the high pressure fluid within said second chamber with said third chamber; a fourth fluid channel connecting said first fluid channel with the exterior of said support; said support comprised of first and second portions connected by a joint intermediate the first-mentioned means and the point of suspension of said support by said wireline; said joint adapted for accommodating a limited amount or" relative movement of said first and second portions; restraining means in bridging relation to said portions restraining said joint against relative movement and maintaining said portions in normal relative positions; balance means on one of said support portions providing an area in wetted relation to borehole fluids tending to equalize the force effects of borehole fluids on said joint; said joint including force unbalance means for efiectuating an unbalance of force on said joint to urge said portions in the direction of said relative movement upon the occurrence of a first predetermined increment of relative movement of said joint; valve means operatively associated with said joint and movable in accordance with relative movement of said portions from a first or normal position establishing a first or normal fluid flow condition in one or" said fluid channels to a second or actuated position establishing a different fluid flow condition in said one fluid channel subsequent to a second predetermined increment of relative movement of said joint; said first and second portions, when said support is in anchored engagement with a borehole wall, adapted to over-ride said restraint means and move relatively said first predetermined increment in response to wireline tension exerted at the earths surface and to move relatively said second predetermined increment of relative movement in response to said unbalance of force, whereby said valve means effectuates a change in the fluid flow condition of said one fluid channel.

2. The device of claim 1 wherein said restraining means comprises a resilient member in biased relation intermediate said first and second portions.

3. The device of claim 2 wherein said resilient member is a coiled spring which is compressed to its stacked condition by said limited amount of relative movement and in said stacked condition functions as a positive limit stop.

4. The device of claim 3 wherein said unbalance means comprises an area, normally in unwetted relation to borehole fluids, but adapted for wetting thereby in response to said first predetermined increment of relative movement to thereby provide an unbalance force of several times the weight of one of said portions to thus impart a high measure of acceleration to said portions in their relative movement until their relative movement is abruptly stopped upon the stacking of said coiled spring, whereupon a shock force is applied by the last-mentioned one of said portions to the other.

5. The device of claim 1 wherein indicating means is provided in bridging relation to said portions for indicating relative displacement from their said normal relative positions.

6. The device of claim 5 wherein said indicating means is adapted to permanently deform in proportion to relative displacement of said portions from their said normal relative positions.

7. T he device of claim 1 wherein locking means is provided on one of said portions for locking the same with respect to the other to thereby prevent said portions from inadvertently returning to their said normal relative positions subsequent to the occurrence of said second predetermined increment of relative movement.

8. A device for obtaining samples of the fluid content of formations traversed by a borehole containing a column of fluid comprising: a support adapted to be suspended in a borehole by means of a wireline from the earths surface and including a first portion connected at its upper end to said wireline and a second portion connected to said first portion by a joint adapted for relative movement in response to a mechanical signal communicated over said wireline from the earths surface; a chamber in said support for receiving a fluid sample; pack-off means mounted on said second portion and having a face for isolating an area of borehole wall when engaged therewith, a fluid inlet in said face for admitting a fluid sample from the isolated area of borehole wall; a fluid channel communicating between said inlet and said cham ber; motive means associated with said second portion of said support and including a pressure chamber responsive to pressure of said column of fluid for moving the face of said pack-ofl means outwardly into engagement with the wall of the borehole; means on said pack-off means normally urging said pack-oil. means inwardly towards a retracted position; and means communicable with said pressure chamber upon relative movement between said first and second portions of said support in response to said mechanical signal for relieving the pressure applied to said motive means to thereby allow said pack-elf means to move inwardly under the influence of said urging means.

9. A device for obtaining samples of the fluid content of formations traversed by a borehole containing a fluid comprising: a support adapted to be suspended in a borehole by means of a Wireline from the earths surface; a chamber in said support for retaining a fluid sample; means on said support responsive to fluid pressure for anchoring said support with respect to the borehole wall and for isolating a portion of borehole wall with respect to borehole fluids; a first fluid channel for conducting a formation fluid sample from within said isolated portion ofborehole wall to said chamber; a second chamber in said support containing a fluid under high pressure for pressurizing said means; a second fluid channel in communication with said second chamber for communicating pressurized fluid thereto; a third chamber in said support containing a compressible fluid at a pressure substantially less than that of the high pressure fluid; a third fluid channel for connecting the high pressure fluid within said second chamber with said third chamber; a fourth fluid channel connecting said first fluid channel with the exterior of said support; a first valve means in said first fluid channel normally establishing fluid communication therein, and, when actuated, adapted to block fluid communication therethrough; a second valve means normally blocking fluid communication from said first to said fourth fluid channel, and, when actuated, adapted to establish fluid communication from said first to said fourth fluid channel; a third valve means in said third fluid channel normally blocking fluid communication therethrough, and, when actuated, adapted to establish fluid communication in said third fluid channel; said support comprised of first and second support portions connected by a joint intermediate the first-mentioned means and the point of suspension of said support by said wireline; said joint adapted for accommodating a limited amount of relative movement of said first and second support portions; restraining means in bridging relation to said support portions restraining said joint against relative movement and maintaining said support portions in normal relative positions; each of said valve means disposed in oneof said support portions and each is adapted to be actuated in response to respectively predetermined increments of relative movement of said first and second support portions; balance means on one of said support portions providing an area in wetted relation to borehole fluids tending to equalize the force effects of borehole fluids on said joint; unbalance means on said one support portion providing an area normally unwetted with respect to borehole fluids, but adapted for wetting thereby in response to a predetermined amount of said relative movement, and when so wetted, achieve an unbalance of force effects of borehole fluids on said joint; said first and second supportportions, when said device is anchored with respect to a borehole wall, adapted to override said restraint means and move relatively in response to movement of said wireline and adapted to complete said limited amount of relative movementresponsive to said unbalance of force effects, whereupon said first, second, and third valve means are actuated to respectively accomplish shut-in of any fluid sample in the firstmentioned chamber, pressure equalization between the isolated portion of borehole wall and the fluid pressure of the borehole, and pressure equalization of said second and third chambers.

. 10. A device for obtaining samples of the fluid content of formations traversed by a borehole comprising: a support adapted to be'suspended in a borehole by means of a wireline from the earths surface; said support comprised of a first portion connected at its upper end to said wireline and a second portion connected to said first portion by a joint adapted to permit a limited amount of relative movement of said portions; restraining means in bridging relation to said portions restraining said joint against relative movement and establishing normal relative positions of said portions; a first chamber in said support for retaining a fluid sample; pack off means mounted on said support and having one surface facing the Walls of said borehole; a fluid channel for providing communication between said chamber and said surface; fluid driven motive means adapted to force the surface of said pack o-tf means against the wall of the said bore- .hole; a second chamber in said support containing a substantially incompressible high pressure fluid for activating said motive means; a third chamber in said support filled with a compressible fluid at substantially less pressure that that of the high pressure fluid; second and third fl-uid channels respectively adapted to fluidly communicate said second and third chambers with said motive means; valve means in one of said portions normally blocking fluid communication in said third fluid channel and adapted to open said communication upon the occurrence of said limited amount of relative movement; said joint including an area normally wetted by borehole fluid and functioning to balance the force effects of borehole fluids on said joint; said joint including force unbalance means for effectauting an unbalance of force on said joint to urge said portions in the direction of said relative movement upon the occurrence of 'a predetermined amount of relative movement; said first and second portions, when said pack off means is against a borehole wall, adapted to over-ride said restraint means and move relatively said predetermined amount in response to movement of said wireline and to complete said limited amount of relative movement responsive to said unbalance of force, whereupon said valve means is opened to accomplish pressure equalization of said second and third chambers.

11. The device of claim 10 wherein said restraining means comprises a resilient member in biased relation intermediate said first and second portions.

12. The device of claim 11 wherein said resilient member is a coiled spring which is adapted for compression to its stacked condition by said limited amount of relative movement and in said stacked condition functions as a positive limit stop.

13. The device of claim 12 wherein said force unbalance means comprises an area on one of said support portions normally un-wetted with respect to borehole fluid, but adapted for wetting thereby in response to said predetermined amount of relative movement, and, when so wetted, applies the force product of said area of said unbalance means and the pressure intensity of borehole fluids to said joint to thus impart a high measure of ac-, Y

celeration to said support portions until relative movement is abruptly stopped by the stacking of said coiled spring, whereupon a shock force is applied by the lastmentioned one of said support portions to the other.

14. The device of claim 10 wherein indicating means is provided in bridging relation to said portions for indicating displacement from their normal relative positions.

15. The device of claim 14 wherein said indicating means is adapted to permanently deform in proportion to relative displacement of said portions from said normal relative positions.

16. The device of claim 10 wherein locking means is provided on one of said portions for locking the same with respect to the other of said portions upon the occurrence of a second predetermined amount of relative movement to thereby prevent said portions from inadvertently returning to their said normal relative positions subsequent to said second predetermined amount of relative movement.

References Cited by the Examiner UNITED STATES PATENTS 2,613,747 10/1952 West 166l00- 2,640,542 6/1953 Brown et al. 16665 2,674,313 4/1954 Chambers 166100 X 2,915,123 12/1959 Lebourg 166100 X 3,010,517 11/1961 Lanmon 166169 X CHARLES OCO'NNEL L, Primary Examiner. 

8. A DEVICE FOR OBTAINING SAMPLES OF THE FLUID CONTENT OF FORMATIONS TRAVERSED BY A BOREHOLE CONTAINING A COLUMN OF FLUID COMPRISING: A SUPPORT ADAPTED TO BE SUSPENDED IN A BOREHOLE BY MEANS OF A WIRELINE FROM THE EARTH''S SURFACE AND INCLUDING A FIRST PORTION CONNECTED AT ITS UPPER END OF SAID WIRELINE AND A SECOND PORTION CONNECTED TO SAID FIRST PORTION BY A JOINT ADAPTED FOR RELATIVE MOVEMENT IN RESPONSE TO A MECHANICAL SIGNAL COMMUNICATED OVER SAID WIRELINE FROM THE EARTH''S SURFACE; A CHAMBER IN SAID SUPPORT FOR RECEIVING A FLUID SAMPLE; PACK-OFF MEANS MOUNTED ON SAID SECOND PORTION AND HAVING A FACE FOR ISOLATING AN AREA OF BOREHOLE WALL WHEN ENGAGED THEREWITH, A FLUID INLET IN SAID FACE FOR ADMITTING A FLUID SAMPLE FROM THE ISOLATED AREA OF BOREHOLE WALL; A FLUID CHANNEL COMMUNICATING BETWEEN SAID INLET AND SAID CHAMBER; MOTIVE MEANS ASSOCIATED WITH SAID SECOND PORTION OF SAID SUPPORT AND INCLUDING A PRESSURE CHAMBER RESPONSIVE TO PRESSURE OF SAID COLUMN OF FLUID FOR MOVING THE FACE OF SAID PACK-OFF MEANS OUTWARDLY INTO ENGAGEMENT WITH THE WALL OF THE BOREHOLE; MEANS ON SAID PACK-OFF MEANS NORMALLY URGING SAID PACK-ORR MEANS INWARDLY TOWARDS A RETRACTED POSITION; AND MEANS COMMUNICABLE WITH 